Double seal closure plug

ABSTRACT

A closure plug for a tubular opening as in the neck of a receptacle or at the end of a conduit, wherein a plug portion enters the opening with a close fit to constitute a mechanical seal, while an outer skirt portion of the plug forms an annular enclosed recess about the exterior of the opening, an axially movable piston in the top of the plug being forced into a cylindrical chamber in the plug to drive a quantity of sealing (sterilizing) liquid from said chamber into the recess to form a liquid barrier seal around the exterior of the opening, the lip of the opening being thus enclosed externally and internally.

United States Patent [191 Frassica [111 3,826,396 [451 Jul 30, 1974 l,45l.937 3,072,83l 3,164,279 3,499,568

DOUBLE SEAL CLOSURE PLUG lnventor: James J. Frassica, South Glens Falls, NY.

Assignee: C. R. Bard, lnc., Murray Hill, NJ. Filed: Oct. 31, 1972 Appl. No.: 302,441

US. Cl. ..215/ 2 1 4, 2] 7;/135 Int. Cl B65d 41/24 Field of Search 215/6, 40, 47, 56, 74,

References Cited UNlTED STATES PATENTS Attorney, Agent, Jr Fi'rm Cl EMartine, Jr.

[57] ABSTRACT A closure plug for a tubular opening as in the neck of a receptacle or at the end of a conduit, wherein a plug portion enters the opening with a close fit to constitute a mechanical seal, while an outer skirt portion of the plug forms an annular enclosed recess about the exterior of the opening, an axially movable piston in the top of the plug being forced into a cylindrical chamber in the plug to drive a quantity of sealing (sterilizing) liquid from said chamber into the recess to form a liquid barrier seal around the exterior of the opening, the lip of the opening being thus enclosed externally and internally.

12 Claims, 7 Drawing Figures DOUBLE SEAL CLOSURE PLUG It is known to provide receptacles and the like with closures which extend both into and around the neck and lip of the receptacle, whether the latter is inside finished or outside finished or neither. Examples of such closures appear in US. Pats. to Towns No. 3,164,279; I-Iuck No. Re.25,l46; Riera No. 3,499,568; and see also Arnold No. 1,451,937 and Morane No. 3,439,823. Such dry closures may be quite effective for many purposes while not necessarily being tight enough to maintain sterility of the part of the receptacle to which they are applied. The present closure plug is designed to make two liquid-proof mechanical seals, inside and outside, and to provide also a barrier seal of liquid, confined between the mechanical seals, which liquid may be in the nature of a sterilant in order to establish and maintain the sterility of the neck and lip of a receptacle (or the end of a conduit).

The closure plug is a two-part device, the plug body being adapted to fit snugly into the passage to be closed and being connected to an integrally formed skirt which fits snugly on the outside of the receptacle neck or conduit end while leaving an annular space about the lip of the neck(or end of the conduit). The plug body has a first outwardly open cylindrical recess connected by a small hole near its upper end to the annular space, and a second, larger outwardly open cylindrical recess into which the first recess opens. The second part of the plug is a double piston, having a stem portion adapted to fit snugly into the first recess and a head portion fitting snugly into the second recess. A portion of the stem adjacent to the head is of a reduced diameter. When the plug is being prepared for use in the neck or conduit end to be closed, the stem of the piston is partially engaged in the first recess, the annular well formed around the stem by the walls of the second recess is partially filled with a quantity of liquid (sterilant) and the piston parts are forced into their respective recesses, the head of the of the piston engaging the wall of the second recess to enclose the liquid. The operation of sealing the opening in a neck or conduit is described below.

A practical embodiment of the invention is shown in the accompanying drawing, wherein:

FIG. 1 represents a vertical axial section through the plug body, with the piston (in elevation) in position for initial assembly;

FIG. 2 represents a section and an elevation of the parts, as in FIG. 1, with the piston partially engaged in the body and sterilizing liquid added;

FIG. 3 is similar to FIG. 2 with the parts in ready-touse position;

FIG. 4 is a vertical axial section through the end of a conduit, to be closed and sealed, with the closure plug engaged therewith to establish a first (mechanical) seal;

FIG. 5, represents a view similar to FIG. 4 with the piston head partially engaged in the upper recess of the plug body and liquid sterilant being forced into its outer sealing space;

FIG. 6 represents a view similar to FIG. with the piston fully seated in the plug body, and

FIG. 7 represents a view similar to FIG. 4 but showing a modified form in which the piston is screw threaded.

Referring to the drawing, the plug body 10 comprises a hollow cylindrical portion 11, closed at its bottom end 12; an annular wall 13 extending radially outward from the top edge of the portion 11; a cylindrical skirt 14 projecting downward from the wall 13, spaced from and parallel to the wall of the portion 11; and a cylindrical collar 15 projecting upward from the wall 13 and being substantially an upward continuation of the skirt 14.

The piston 16 comprises a cylindrical stem 17 and head 18, the stem being of a size to fit snugly within the portion 11 of the plug and the head fitting tightly within the collar 15 of the plug. A portion 19 of the stem, just below the head, is of slightly reduced diameter, for a purpose to be explained.

The opening 20 to be closed, whether it is in the neck of a receptacle or in a fitting on the end of a pipe, tube or other conduit (all hereinafter designated as tube adapter) is preferably of a special design, as indicated in FIGS. 4,5,6 and 7, in that its end 21 is externally annularly rabetted (or beveled) as shown at 22, and an annular radially projecting flange 23 is spaced axially from the end 21 by a distance less than the axial length of the skirt 14, a portion 24 of the tube adapter wall (e.g., adjacent the flange 23) being of a size to fit snugly within said skirt. I

A radial passage 25 is provided through the wall of the portion 11 a short distance below the wall 13 and an air bleed hole 26 may be provided in the upper part of the skirt 14, the hole 26 (if present) being filled with a microporous material, not shown, to permit passage of air while restricting leakage of liquid.

The two-part plug is prepared for use by engaging the piston 16 with the body portion 10 approximately as shown in FIG. 2. A quantity of liquid (sterilant) L is placed, as from a syringe S, in the well formed by the collar 15 and stem 17, the quantity being limited to permit depression of the piston head 18 into engagement with the collar 15, as shown in FIG. 3. Liquid-filled plugs according to FIG=3 may be packaged individually or in bulk, and preferably sterile, for use when needed.

When it is desired to close the opening in a tube adapter 20, having the special features described above, the plug 10 is fully seated within the tube adapter opening (FIG. 4), the skirt l4 engaging the wall portion 24 and its lower edge resting on the flange 23 so as to hold the wall 13 a short distance above the end 21 of the adapter, whereby the passage 25 remains open and in communication with the annular space 27 resulting from the rabetting or beveling 22 of the adapter end 21. As the piston 16 is forced downward (FIG. 5) the liquid L is put under pressure and, with the reduced portion 19 in register with passage 25, flows past the reduced portion, through the passage and into the space 27. The air occupying said space is vented through the hole 26 (or leaks out past the skirt 14 if the hole 26 is omitted) and when the piston head 18 has been fully seated within the collar 15, as shown in FIG. 6, the seal is complete. The interior of the tube 20 is closed by the plug body portion 11, the edge 21 is immersed within the sealing liquid filling the space 27 and the skirt 14 is engaged with the wall portion 24. The piston 16 cannot be withdrawn because its head is flush with the top edge of the collar 15,, but the whole plug can be removed from the tube adapter whenever desired by pulling, with or without a twisting component.

Amodified form of plug is shown in FIG. 7 wherein the plug body 30 and piston stem 31 are threaded and the piston head 32 is provided with a slot 33. The threaded'stem' 31 has a reduced diameter portion '34, corresponding to the portion 19 (FIGS. 1 to 6) and the sealing operation is the same as described above except that depression of the piston is effected by screwing instead of mere downward pressure.

The pistonhead 18 or 32 must, in either form, have a leak-proof fit within the collar 15 or 35 (FIG. 7) and this may be ensured by the provision of an O-ring 36 (FIG. 7) or a slight interference fit. or by the use of some other sealing means.

The closure plug could, if desired, be used to close the end of a plain tube or hose, or the neck of a container with neither inside nor outside finish, if the diameters of the plug body and skirt are suitably coordinated with the ID. and CD. of the tube, hose or container and the plug is applied only to a distance such that the wall 13 is spaced from the lip of the tube, hose or container, thus leaving an annular channel above the lip to receive sealing liquid.

It is evident that the closure plug disclosed herein can be used in connection with any suitably formed tube adapter, particularly in situations where the opening is required to be maintained in a clean and sterile condition, since the liquid seal around the lip of the opening between inner and outer mechanical seals reliably prevents the entry of any air or liquid borne contaminent. As a specific example of one field of utility reference may be made to Tolle et al. US. Pat. No. 3,653,359, Apr. 4, 1972, Method and Apparatus for Milking Dairy Animals by Means of a Catheter, wherein the present closure plug may desirably be substituted for the cap (FIG. 1) or valve and spigot (FIG. 13) to maintain sterility of the system, as required.

It will be understood that various changes may be made in the form, construction and arrangement of the several parts without departing from the spirit and scope of the invention and hence I do not intend to be limited to the details shown or described herein except as the same are included in the claims or may be required by disclosures of the prior art.

What I claim is:

l. A closure plug for a tubular opening comprising a plug body portion and a piston, the plug body portion having a cylindrical part adapted to fit in the opening to be closed, a skirt portion located radially outward from the cylindrical part and adapted to fit against an outer surface, of the device having a tubular opening, means connecting the skirt portion and the cylindrical part to form therebetween an inverted annular channel, an annular collar projecting upwardly from said means and presenting a smooth cylindrical inner wall surface, and the piston having a stem and a head, the stem being adapted to fit within the cylindrical part, the head being adapted to fit within the collar and the stem having a reduced cross-sectional area adjacent the under side of the head, the wall of the cylindrical part being traversed by a radial passage connectingthe interior of said part with the annular channel.

2. A closure plug according to claim 1 wherein the height of the piston head is substantially equal to the height of the collar. I

3. A closure plug according to claim 1 wherein the skirt is provided with a radially disposed air vent.

4. A closure plug according to claim 3 wherein the radial passage and the air vent are located at points near the connecting means.

5. A closure plug according to claim 1 which includes a quantity of liquid confined in the annular space defined by the wall surface of the collar, the under side of the head, and the reduced area portion of the piston stem.

6. A closure plug according to claim 1 wherein the cylindrical part and the piston stern are complementarily screw threaded.

7. In combination, a tube adapter having a tubular opening to be closed and presenting cylindrical inside and outside surfaces adjacent said opening, with a lip between said surfaces and a closure plug for said opening, the closure plug comprising a plug body portion and a piston, the plug body portion having a cylindrical part fitting against said inside surface, a skirt portion located radially outward from the cylindrical part and fitting against said outer surface, means connecting the skirt portion and the cylindrical part to form therebetween an inverted annular channel, an annular collar projecting upwardly from said means and presenting a smooth cylindrical inner wall surface, and the piston having a stem and a head, the stem being fitted within the cylindrical part, the head being fitted within the collar and the stem having a reduced cross-sectional area adjacent the under side of the head, the lip being spaced from the connecting means to form an annular sealing space and the wall of the cylindrical part being traversed by a radial passage connecting the interior of I said part with the annular sealing space.

8. The combination according to claim 7 wherein the height of the piston head is substantially equal to the' and the cylindrical outside surface. 

1. A closure plug for a tubular opening comprising a plug body portion and a piston, the plug body portion having a cylindrical part adapted to fit in the opening to be closed, a skirt portion located radially outward from the cylindrical part and adapted to fit against an outer surface of the device having a tubular opening, means connecting the skirt portion and the cylindrical part to form therebetween an inverted annular channel, an annular collar projecting upwardly from said means and presenting a smooth cylindrical inner wall surface, and the piston having a stem and a head, the stem being adapted to fit within the cylindrical part, the head being adapted to fit within the collar and the stem having a reduced cross-sectional area adjacent the under side of the head, the wall of the cylindrical part being traversed by a radial passage connecting the interior of said part with the annular channel.
 2. A closure plug according to claim 1 wherein the height of the piston head is substantially equal to the height of the collar.
 3. A closure plug according to claim 1 wherein the skirt is provided with a radially disposed air vent.
 4. A closure plug according to claim 3 wherein the radial passage and the air vent are located at points near the connecting means.
 5. A closure plug according to claim 1 which includes a quantity of liquid confined in the annular space defined by the wall surface of the collar, the under side of the head, and the reduced area portion of the piston stem.
 6. A closure plug according to claim 1 wherein the cylindrical part and the piston stem are complementarily screw threaded.
 7. In combination, a tube adapter having a tubular opening to be closed and presenting cylindrical inside and outside surfaces adJacent said opening, with a lip between said surfaces and a closure plug for said opening, the closure plug comprising a plug body portion and a piston, the plug body portion having a cylindrical part fitting against said inside surface, a skirt portion located radially outward from the cylindrical part and fitting against said outer surface, means connecting the skirt portion and the cylindrical part to form therebetween an inverted annular channel, an annular collar projecting upwardly from said means and presenting a smooth cylindrical inner wall surface, and the piston having a stem and a head, the stem being fitted within the cylindrical part, the head being fitted within the collar and the stem having a reduced cross-sectional area adjacent the under side of the head, the lip being spaced from the connecting means to form an annular sealing space and the wall of the cylindrical part being traversed by a radial passage connecting the interior of said part with the annular sealing space.
 8. The combination according to claim 7 wherein the height of the piston head is substantially equal to the height of the collar.
 9. The combination according to claim 7 wherein the skirt is provided with a radially disposed air vent.
 10. The combination according to claim 7 wherein the radial passage and the air vent are located at points near the connecting means.
 11. The combination according to claim 7 which includes a quantity of liquid within the sealing space adjacent to the lip.
 12. The combination according to claim 11 wherein the tube adapter is shaped to provide an enlarged sealing space radially outward from the lip, between the lip and the cylindrical outside surface. 